恶臭源厂界空气中恶臭物质监测技术要点及结果分析探讨——以西安市某大型垃圾填埋场为例

建立了水杨酸-次氯酸钠法分析氨的标准曲线,通过对西安市某垃圾填埋场的实地监测,探索了恶臭气体中氨气的分析方法。分析了臭气、氨气、硫化氢之间的浓度相关性,利用本次监测数据,找出了针对该垃圾处理场的高浓度氨气样品初步分析方案。恶臭产生的主要点位为垃圾场渗滤液污水处理站及下游区域,垃圾场臭气呈现出由点源污染(作业面)到面源污染扩散的态势。     

北京入境旅游流西向扩散与省域经济联系研究——以西部三大典型区为例

北京是我国经济、政治和文化中心,也是我国最重要的入境口岸之一。入京旅游流西向的扩散转移对省域之间旅游经济联系强度具有极大的直接促进作用,转移态是反映旅游流流向和流量的重要指标。在对我国西部三大典型旅游区界定的基础上,利用转移态指数模型和旅游经济联系强度模型对入京旅游流向西转移态及其与西部三大典型旅游区的经济联系强度进行了相关性分析,得出入京旅游流西向转移态对西部典型区经济的影响程度为:成渝泛西安云贵,在此基础上分析了原因,并对西部三大典型旅游区如何更好地吸引北京入境旅游"二手客源",以促进旅游业更快发展提出了相应对策与建议。     

中国能源生态足迹的时空动态特征及效应分析

运用生态足迹方法计算出1990—2007年中国能源消费的生态足迹。在此基础上,分析了能源足迹强度(EFI)、能源足迹生态压力(EPIEF)的时空动态变化特征。结果表明,近20年来我国能源足迹波动上升,能源消费结构有所改善,但煤炭足迹仍占主导,近几年又有回升趋势;能源足迹强度呈幂指数衰减,能源利用效率不断提高;EPIEF呈上升趋势,说明能源利用对自然生态系统的压力逐渐增大。在空间分布上,各省区能源足迹差异显著,能源足迹强度由西向东逐渐降低,而EPIEF则由西向东呈增大趋势。依据EPIEF指数将中国30个省区划分为能源足迹生态盈余区(EPIEF1)、生态轻度亏损区(1EPIEF5)和生态严重亏损区(EPIEF5)3种类型。     

臭味去除技术进展与分析

臭味问题作为日益严重的环境问题,越来越受到人们的重视,臭味控制和去除技术还有许多工作需要开展。本文先介绍了臭味的成因,然后对当前主流的除臭技术进展(物理除臭,化学除臭,生物除臭)进行了综述,重点分析介绍了生物除臭中的土壤除臭技术。文章最后对各种除臭技术进行了比较,并对未来的除臭技术进行了分析和展望。     

天津市纪庄子污水处理厂恶臭气体排放研究

2011年,在天津市纪庄子污水处理厂内采集空气样品,并对其中恶臭气体的浓度、扩散模式、影响范围及污水厂内各主要构筑物间相关系数进行了分析研究。结果表明,污水处理厂格栅处恶臭气体浓度最高,为4.31 ng/mL,其中95.61%为H2S气体,其他构筑物恶臭气体浓度范围为0.09～0.32 ng/mL,恶臭气体浓度较前处理工艺相比有大幅度减少;各主要构筑物排放的恶臭气体符合高斯气体扩散模式,恶臭影响范围为厂界外100 m以内;格栅处恶臭气体的排放对于厂界处恶臭气体浓度的贡献度最大,为42.68%;格栅、初沉池、脱水机房、二沉池之间的相关度在90%以上。     

Rain‐washing of foliar deposits of Dimilin®WP‐25 formulated in four different carrier liquids

Abstract

Dimilin^® WP‐25, a wettable powder formulation of diflubenzuron (DFB) [1‐(4‐chlorophenyl)‐3‐(2,6‐difluorobenzoyl) urea], was formulated in four different carrier liquids, viz., water; a light petroleum paraffinic oil, ID 585; a heavy paraffinic oil, Sunspray^® 7N; and a 1:2 mixture of a light petroleum aromatic solvent (Cyclosol^® 63) and canola oil; to provide four end‐use mixtures, Dim‐W, Dim‐585, Dim‐7N and Dim‐Cy‐C respectively, each containing 28 g of DFB per litre. Balsam fir branch tips clipped from greenhouse‐grown seedlings, and sugar maple branch tips clipped from field‐grown young trees, were exposed to uniform‐sized droplets (ranging in diameters from 135 to 190 μm) of the four end‐use mixtures which were atomized using a monodispersed droplet generator. Droplets were collected on the fir and maple branch tips and the initial residue per g fresh weight of foliage was determined by high‐performance liquid chromatography (HPLC). The branch tips were exposed to cumulative rainfall of 3, 6 and 10 mm at an intensity of 5 mm/h and at time intervals of 1, 12, 36 and 72 h after DFB treatment, to test the influence of ‘ageing’ of foliar residues on rainfastness. Foliar samples were collected for residue determination just before the onset of rainfall, and at 0.5 h post‐rain. DFB was quantified by the HPLC method. In the case of fir foliage, the Dim‐W formulation was the most susceptible to rain‐washing and the rainfastness did not increase with the ageing period of foliar deposits. In contrast, the three oil‐based mixtures showed greater rainfastness depending upon the carrier liquid and the ageing period. Rainfastness decreased in the order of Dim‐Cy‐C > Dim‐7N > Dim‐585 > Dim‐W. In contrast, the data on maple foliage indicated that the ageing of deposits increased the rainfastness of all the 4 end‐use mixtures. Dim‐585 was the most susceptible to rain washing, and rainfastness decreased in the order of Dim‐W > Dim‐Cy‐C > Dim‐7N > Dim‐585.     

伊朗加恩—贝尔兼德地震结构震害概述

对１９９７年５月１０日伊朗东部加恩－贝尔兼德地震中出现的几类结构的震害现象进行了初步的描述与分析,同时,就经抗震设防与未防抗震设防结构的震害现明作了对比。对震区重建及附近地区新建结构抗震问题的解决有一定的参考意义。     

Hermaphrodite sex role preferences: the role of partner body size, mating history and female fitness in the sea slug Chelidonura sandrana

Costs and benefits associated with matings and the effects of mating frequency on fitness commonly differ between the sexes. As a result, outcrossing simultaneous hermaphrodites may prefer to copulate in the more rewarding sex role, generating conflicts over sperm donation and sperm receipt between mates. Because recent sex role preference models remain controversial, we contrast here some of their assumptions and predictions in the sea slug Chelidonura sandrana. For this hermaphrodite with sperm storage and internal fertilisation, risk-averse models assume that fitness pay-offs are constantly higher in the female than in the male function in any single mating. Moreover, excluding mutual partner assessment, these models predict male mating behaviour to be independent of receiver traits. The competing gender ratio hypothesis assumes that relative fitness pay-offs, and thus the preferred mating roles, vary and may reverse between matings and predicts that ejaculation strategies co-vary with receiver quality. We found that field mating rates of C. sandrana substantially exceeded what is required to maintain female fertility and fecundity, indicating large variation in direct female benefits between matings. We further demonstrate that male copulation duration adaptively increased with partner body size (i.e. fecundity) but decreased with recent partner promiscuity. These findings are compatible with the gender ratio hypothesis but contradict risk-averse models.     

长江三角洲及其附近地区两千年来水灾的研究

通过对长江三角洲及其附近地区两千年来水灾生成频率和强度的分析。认为两晋、南北朝时期和南宋、元、明、清时期是两千年来本区的主要水灾期。对照两千年来中国东部气候变化、海面升降与长江口河道变迁关系,认为在本区水灾生成事件中,气候因素起着主导控制作用。当然,人类活动对本区水灾生成的影响也不容忽视。本地区近百年来的旱涝灾害规律可用非线性科学的方法进行研究,旱涝灾害的准60年、准35年和准11年的长周期变化与地球自转速度、地极移动和太阳黑子活动的3个周期变化基本一致。本地区气候系统的行为具有混沌特征。这是线性逼近和周期叠加预报方法难以得出灾害预报正确结果的原因,但气候系统半个月的确定性预测可以实现。     

Determination of turbulent burning velocities of dust air mixtures with the open tube method

Correlating turbulent burning velocity to turbulence intensity and basic flame parameters-like laminar burning velocity for dust air mixtures is not only a scientific challenge but also of practical importance for the modelling of dust flame propagation in industrial facilities and choice of adequate safety strategy. The open tube method has been implemented to measure laminar and turbulent burning velocities at laboratory scale for turbulence intensities in the range of a few m/s. Special care has been given to the experimental technique so that a direct access to the desired parameters was possible minimising interpretation difficulties. In particular, the flame is propagating freely, the flame velocity is directly accessible by visualisation and the turbulence intensity is measured at the flame front during flame propagation with special aerodynamic probes. In the present paper, those achievements are briefly recalled. In addition, a complete set of experiments for diametrically opposed dusts, starch and aluminium, has been performed and is presented hereafter. The experimental data, measured for potato dust air mixtures seem to be in accordance with the Bray Gülder model in the range of 1.5 m/s<u′<3.5 m/s. For a further confirmation, the measurement range has been extended to lower levels of turbulence of u′<1.5 m/s. This could be achieved by changing the mode of preparation of the dust air mixture. In former tests, the particles have been injected into the tube from a pressurised dust reservoir; for the lower turbulence range, the particles have been inserted into the tube from above by means of a sieve–riddler system, and the turbulence generated from the pressurised gas reservoir as before. For higher levels of turbulence, aluminium air mixtures have been investigated using the particle injection mode with pressurised dust reservoir. Due to high burning rates much higher flame speeds than for potato dusts of up to 23 m/s have been obtained.